SILVER SPRING, Md. — The Food and Drug Administration's Nonprescription Drugs Advisory Committee on Friday voted against Merck's application to switch its Oxytrol patch from prescription-only to over the counter, citing concerns over use of therapy for an overactive bladder in women without a doctor's intervention.

The committee voted five in favor and six opposed, also citing concerns that men might inappropriately choose to use the product as well.

Panelists opposed to the switch suggested that consumers would have a difficult time self-diagnosing an overactive bladder, as symptoms are similar to those of a number of more serious conditions like bladder malignancy or diabetes.

Proponents of the switch argued that women with overactive bladders may go years before consulting a physician and that an OTC option might encourage therapy sooner.

The Drug Facts label of the proposed OTC Oxytrol patch included a warning that use should be restricted to two weeks if it doesn't work.

The FDA is expected to issue a decision on the switch application in January 2013.